JPH021850Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a transformer used as a high-voltage transformer for microwave ovens, etc., and is intended to improve the quality of the transformer by improving the insulation of the coil with respect to the iron core.

A transformer used in a conventional microwave oven was constructed as shown in FIGS. 1 and 2.

That is, a rectangular cylindrical bobbin 2 is fitted into the central magnetic leg of an E-shaped core 1 made of laminated E-shaped laminated cores, and U-shaped insulators 3 are covered on both sides of the bobbin 2, and end insulating plates 8 are covered with interlayer paper. A secondary coil 4 insulated from the E-shaped core 1 is attached to the end face of the portion of the wound secondary coil 4 that extends outside the core, and a heater coil 5 and a primary coil 6 are attached to the heater coil 5. A shunt core 7 is inserted between the primary coils 6, and an I-shaped core 9, which has I-shaped laminated cores laminated, is brought into contact with the end face of the E-shaped core 1.

With such a configuration, the secondary coil 4
A bobbin 2, a U-shaped insulator 3, and an end face insulating plate 8 are required for insulation, which requires time and effort to assemble, which is disadvantageous in terms of cost, and it is easy to forget to install insulating materials, which also poses quality problems. In addition, if a burr or the like were formed on the end face of the central magnetic leg of the E-type iron core 1 when the secondary coil 4 was assembled, there was a risk that the inner peripheral surface of the secondary coil 4 would be damaged and layer shorts would occur.

The present invention eliminates the above-mentioned drawbacks of the prior art.

An embodiment of the present invention will be described below with reference to FIGS. 3 to 8. Reference numeral 10 denotes an E-type core constructed by laminating E-type laminated cores, and a secondary coil 11 and a heater coil 12 are installed in the central magnetic leg of this E-type core 10.
A shunt core 1 is placed between the heater coil 12 and the primary coil 14, and the primary coil 14 is installed.
5 is inserted, and an I-shaped core 16 formed by laminating I-shaped laminated cores is brought into contact with the end face of the E-shaped core 10, and the I-shaped core 16 is joined by welding or the like to form a transformer.

As shown in FIG. 5, the insulating sheet 13 is a press board with a thickness of 0.3 to 1.0 mm.
It is made of polyester film, aramid paper, etc. That is, both outer plates 18 and 19 are provided around the bottom plate 17, and these outer plates 1
Continuing from 8 and 19, respectively, are upper plates 20 and 21,
Both inner side plates 22 and 23 are provided continuously to the top plates 20 and 21, respectively, and the portions indicated by broken lines are bendable. In addition, an H-shaped notch 24 is formed in the middle of the bottom plate 17 to form an opening into which the central magnetic leg of the E-shaped core 10 is inserted. A tongue piece 25 is formed along the side surface. Furthermore, an L-shaped terminal portion 2 is provided at the center of the upper side of the bottom plate 17.
6 is provided so as to protrude outward, and this terminal portion 26 has a terminal 2 for connecting the lead wire of the coil.
7 is provided, and the terminal portion 26 provided with this terminal 27 is insulated by the remaining bent piece 28.

In addition, the top plates 20, 21 of both inner side plates 22, 23
A cut 29 is made inward from the upper and lower sides of the boundary line between the
3 is bent at a right angle to form a corner reinforcing piece 30, which overlaps the tongue piece 25 and extends along the inner surfaces of the secondary coil 11 and heater coil 12.

The insulating sheet 13 is assembled as shown in FIG. 6 by bending the portion indicated by the broken line, and the insulating sheet 13 in this state is laminated with the secondary coil 11 and the heater coil 12 as shown in FIG. The inner plates 22 and 23 are folded inside both coils, the bent piece 28 of the terminal part 26 is bent and overlapped, and the tongue piece 25 is formed by the H-shaped notch 24 of the bottom plate 17.
is folded inside both coils, and the terminal portion 26 is bent along the outer peripheral surface of the secondary coil 11 to obtain the structure shown in FIG.

In addition, in the above embodiment, a high voltage transformer for a microwave oven is shown as an example, so the heater coil 12, shunt iron core 15, etc. are required.
In the case of a power transformer, etc., it is composed of a secondary coil 11 and a primary coil 14, but in this case, the secondary coil 11 or the primary coil 14 may be covered with the above-mentioned insulating sheet 13. , the iron core can also be of EE type.

In addition, a notch 31 of 3 to 5 mm is made at the corner of the bent portion of the tongue piece 15 on the bottom plate 17 of the insulating sheet 13 so as to connect to the opening for inserting the central magnetic leg of the E-shaped core 10. Secondary coil 1
If you pull out the leader line at the beginning of winding 1 and position it,
When attached to the E-type iron core 10, it does not rub against the corner of the central magnetic leg, and there is no fear of breakage of the leader wire.

As the transformer of the present invention is constructed as described above, the insulation between the core and the coil can be achieved only with the insulation sheet that covers the outer periphery of the coil, reducing the number of insulating parts to one, greatly improving the work efficiency of assembly. This improves the performance and reduces costs, and there is no slippage of the insulating sheet against the coil, resulting in extremely stable insulation, and when it is assembled into the iron core, burrs of the iron core can damage the coil and cause layer shorts. The terminal part can also be formed from a part of this insulating sheet without any fear, and the number of parts can be reduced in this respect. In addition to providing a notch so that the lead wire is connected to the core, the lead wire at the end of the coil covered by the insulating sheet is pulled out and positioned through the cut, which eliminates the risk of the lead wire rubbing against the corner of the core and breaking. It is of great practical value.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a conventional transformer, Fig. 2 is an exploded perspective view of the same, Fig. 3 is a perspective view showing an embodiment of the transformer of the present invention, Fig. 4 is an exploded perspective view of the same, and Fig. 5 is an exploded perspective view of the same. Developed diagram of the insulating sheet used in the transformer, No. 6
8 are perspective views showing the assembled state of the insulating sheet. 10...E type iron core, 11...Secondary coil, 12
... Heater coil, 13 ... Insulation sheet, 14 ...
Primary coil, 15...Shunt core, 16...I
Shaped iron core, 17... Bottom plate surface, 18, 19... Outer plate, 20, 21... Top plate, 22, 23... Inner plate, 24... H-shaped notch, 25... Tongue flat, 26...
...Terminal part, 27...Terminal, 28...Bend piece, 29
... cut, 30 ... corner reinforcement piece, 31 ... cut.

Claims (1)

[Scope of utility model registration request] In a transformer in which at least a primary coil and a secondary coil are wound around the central magnetic leg of an EI type or EE type iron core, an opening for inserting the iron core is formed by bending it at an H-shaped notch provided in the center, and the A bottom plate that extends the bent tongue along the inner surface of the coil, an outer plate located on both sides of this bottom plate, a top plate located outside of this outer plate, and a top plate located outside of this top plate. Inner plates are continuously provided at both ends to serve as corner reinforcing pieces by folding them along the inner surface of the coil so as to overlap with the tongue pieces, and an insulating sheet is bent at each boundary thereof. at least one of the coils is covered by the insulating sheet, and the insulating sheet is located at an upper corner of the opening for inserting the iron core in the bottom plate of the insulating sheet and is connected to the opening and covered by the insulating sheet. A notch is provided for drawing out the lead wire of the coil, the end of the coil covered by the insulating sheet is drawn out through the notch, and a terminal portion having a terminal is integrally provided at the center of the upper side of the bottom plate of the insulating sheet. Trance.